JP5173984B2 - Method for producing formula milk - Google Patents

Description

  The present invention relates to a method for producing a formula milk that has reduced deterioration due to oxidation of fats and oils and has a good flavor even when stored for a long period of time.

  Milk represented by cow's milk (raw milk) is a food with excellent nutrition but is not suitable for storage. Therefore, milk powder that has been dried so that raw milk is suitable for storage, and skim milk powder that is suitable for long-term storage by removing fat have been produced for a long time. Nowadays, the production of milk powder will become more precise, and the formula and milk powder will be manufactured by changing the ingredients and composition to be suitable for human beings and further adjusting for growth stage, age, physical condition and disease etc. It has become.

  Generally, formula milk is manufactured by once manufacturing liquid formula milk which mixed and melt | dissolved the raw material containing a various component, and drying this liquid formula milk into powder. As important components added to formula milk, there are various lipids and trace metal elements.

  Lipids are essential nutrients for eating habits and are taken into the body mainly by ingestion of food and drink. Examples of lipids include animal fats and vegetable fats, and examples of animal fats include milk fat obtained from cows, buffalos, goats, donkeys, etc., pork oil (lard), fish oil, and the like. Examples of vegetable oils and fats include oils and fats obtained by culturing microorganisms, in addition to oils and fats obtained from plants such as soybean oil, corn oil, sesame oil, and sesame oil.

  2. Description of the Related Art In recent years, various components such as foods and drinks, particularly infant foods, nutritional functional foods, and foods for specified health use have been improved due to the development of nutrition and changes in nutritional requirements. In fats and oils, the nutritional characteristics of unsaturated fatty acids are attracting attention. Foods and beverages that contain and enhance unsaturated fatty acids such as docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), linoleic acid, linolenic acid, and arachidonic acid It has been released. In the production of formula milk, the addition of fats and oils containing these unsaturated fatty acids is important.

  However, it is known that unsaturated fatty acids are very easily oxidized due to the presence of unsaturated bonds in the fatty acid structure. Oxidation of fats and oils containing unsaturated fatty acids is easily promoted by light, temperature, oxygen and the like.

  For this reason, when fat-containing foods, especially those containing unsaturated fatty acids, are stored for a long period of time, they are oxidized and give off unpleasant odors, which deteriorates the taste and reduces the commercial value.

  For example, DHA, which is an unsaturated fatty acid made from fish such as tuna, may generate a fishy odor called a return odor along with an oxidized odor due to oxidation of DHA. These odors, like the oxidative odor, cause flavor deterioration and significantly reduce the product quality.

  In general, as factors that promote the oxidation of oil, 1) the influence of oxygen, 2) the influence of temperature, 3) the influence of metal ions, 4) the influence of light, and the like are known.

  For example, metal ions such as copper, iron, zinc, manganese, chromium, nickel, and cobalt act as an oxidation catalyst that promotes oxidation of fat-containing foods. Therefore, in the process of pretreatment, production, storage, etc., considering only from the viewpoint of suppressing oxidation of fats and oils, mixing of metals and fats and oils should be avoided.

  However, for example, trace metal elements are essential as components of infant formula, and are very important for human growth. For this reason, in formula milk powder, it became a problem that the unsaturated fatty acid added as an essential component will be oxidized by the metal salt added as an essential component.

  As described above, in the production of formula milk, in general, at the preparation stage in the production process, as a component of liquid formula milk, fats and oils containing unsaturated fatty acids, proteins, sugars, minerals such as metal salts, vitamins, etc. The raw materials are dissolved and mixed. Subsequently, this mixed solution is heated as necessary at each stage of sterilization, concentration, and drying, and is exposed to a high temperature. That is, in the production stage, contact between the oil and fat component and the metal component is unavoidable, and since it is exposed to a high temperature during the production, the oil and fat are easily oxidized.

  Further, the oxidation of fats and oils proceeds in a chain once the oxidation has started, even after removing conditions where oxidation is likely to start. For this reason, it is very difficult to stop the progress of oxidation once started. Therefore, even an oxidation chain reaction started under temporary conditions at the time of production proceeds without end as the storage period becomes longer. For this reason, it has been particularly important to avoid conditions that tend to initiate oxidation even during production.

  Thus, in formula milk containing fats and oils and metal salts, avoidance of oxidation start conditions for fats and oils components during production processes and product storage is urgent from the viewpoint of improving quality, maintaining flavor, extending shelf life, etc. Met.

  Therefore, in the production of conventional formula powdered milk, a method has been adopted in which the addition of the metal salt is performed in the later steps as much as possible. As such a method, there are roughly two methods.

  One method is a method in which an aqueous solution of a metal salt is added to an aqueous solution (liquid formula) (but not including a metal salt) immediately before the liquid formula is dried to a powder. In this method, an aqueous solution of a metal salt is added to liquid formula milk that does not contain a metal salt, and immediately after mixing the two aqueous solutions, the powdered milk is produced by instantaneously heating and drying. For this reason, the time during which the metal salt in the aqueous solution is in contact with the components of the liquid formula is extremely short. Although this method is a practical method, heating after the addition of an aqueous solution of a metal salt is a process that should be avoided as much as possible, and it is extremely accurate in managing the time from mixing to heat drying. There is a problem that work is required. In addition, this method can produce formula milk, but it cannot be used to produce liquid formula.

  Another method is a method of producing a formula milk powder by mixing a powder obtained by drying liquid formula milk (but not including a metal salt) and a powder containing a metal salt (see, for example, Patent Document 1). . In this method, since the metal salt is added and mixed in the powder state, it is impossible in principle that the metal salt in the aqueous solution contacts the components of the liquid formula. Although this method is a practical method, uniform mixing of powders is more difficult than uniform mixing of liquids, and there is a problem that high technology and complicated processes are required. In addition, this method can produce formula milk, but it cannot be used to produce liquid formula.

  In addition to the two methods described above, several methods have been tried. For example, a method using a metal-bound lactoferrin in which lactoferrin known as a metal-binding protein is bound to a metal (Patent Document 2), a method using a metal-bound casein (Patent Document 3), and β-lactoglobulin as an active ingredient And a method using an antioxidant (Patent Document 4). However, both of these are practical because it is necessary to prepare a considerable amount of a specific protein component, the amount of metal that can be added is limited, or the effect is insufficient. It has not been considered as an effective method. For example, in the technique of Patent Document 2, lactoferrin has a small content of 0.02 to 0.2 mg / ml in milk (for example, Clinical Neonatal Nutrition, Kanbara Publishing, 1995, p. 140). It was necessary to purify lactoferrin from milk. In the technique of Patent Document 3, the amount of iron-bound casein and copper-bound casein is 0.01 to 30 mg% by weight of the solid content of the nutritional composition, and the weight of the iron and copper is in the nutritional composition. The amount of metal that can be added was limited. Moreover, in the technique of patent document 4, it was necessary to contain (beta) -lactoglobulin 15-30 weight% with respect to the fats and oils of fats and oils containing foodstuffs. Moreover, when the fat and oil-containing food contains 20 ppm or more of transition metal, it is necessary to add 20 to 40% by weight of β-lactoglobulin, and a considerable amount of β-lactoglobulin is required.

JP-A-6-245698 Japanese Patent Laid-Open No. 10-176000 JP-A-8-98647 JP 2000-104064 A

  Thus, there has been a demand for a method for producing a prepared milk powder that can reduce deterioration due to oxidation of fats and oils and has a good flavor even when stored for a long period of time. In particular, there is a method for producing a formula powder that can be stored for a long period of time without the fat and oil contained as an essential component in formula milk being accelerated by oxidation by the metal component that is also contained as an essential component and causing a deterioration in flavor. Sought.

  Therefore, the objective of this invention is providing the manufacturing method of the preparation milk powder to which the metal element was added and the oxidation of fats and oils was suppressed.

  The inventors of the present invention have made extensive studies to achieve the above-mentioned object. As a result, in the production of formula milk, attention is paid to copper among metal elements, and copper is previously combined with whey protein as a source of copper. The technology using copper-bound whey protein has been reached.

  And the present inventors manufactured the formula milk containing an unsaturated fatty acid using the said copper bond whey protein solution. As a result, the manufactured formula was found that the peroxide value, which is an oxidation index, was effectively suppressed, and the flavor deterioration was also suppressed, and the present invention was completed. According to the present invention, even when a large amount of trace metal elements are added to formula milk, it is sufficient if a pretreatment is performed only on copper and added as a copper-bound whey protein. Oxidation suppression was realized.

That is, this invention which solves the said subject is a method including the process of the following 1) and 2) in the manufacturing method of formula milk.
1) A step of preparing a copper-bound whey protein solution by mixing copper and whey protein in a liquid, wherein the ratio of the mass of copper bound to whey protein to the mass of copper is 80% or more. Process,
2) A process for producing prepared milk by mixing the prepared copper-bound whey protein solution and a raw milk material composed of protein, fats and oils containing unsaturated fatty acids, sugars, vitamins, and minerals, and sterilizing by heating. .

  The first invention of the present invention is that the whey protein in the step 1) has a concentration of 0.7 to 8.0% by mass, and copper and milk mixed in the liquid in the step 1). The milk protein is 60 parts by weight or more with respect to 1 part by weight of copper, and the peroxide value of the prepared milk when the prepared milk is stored at room temperature for 2 months is 0.8 meq / kg. The preferred embodiment is that the amount of hexanal contained in the formula when the prepared formula is stored for 2 months at room temperature is 0.6 ppm or less.

The present invention also includes the following [1] to [5].
[1]
In the method for producing formula milk, the method comprises the following steps 1) and 2):
1) A step of preparing a copper-bound whey protein solution by mixing copper and whey protein in a liquid, wherein the ratio of the mass of copper bound to whey protein to the mass of copper is 80% or more. Process,
2) A process for producing prepared milk by mixing the prepared copper-bound whey protein solution and a raw milk material composed of protein, fats and oils containing unsaturated fatty acids, sugars, vitamins, and minerals, and sterilizing by heating. .
[2]
The method according to [1], wherein the whey protein in the step 1) has a concentration of 0.7 to 8.0% by mass.
[3]
Copper and whey protein to be mixed in the liquid in the step 1)
The method according to [1] or [2], wherein whey protein is 60 parts by mass or more with respect to 1 part by mass of copper.
[4]
The method according to any one of [1] to [3], wherein when the prepared formula is stored at room temperature for 2 months, the formula has a peroxide value of 0.8 meq / kg or less.
[5]
The method according to any one of [1] to [4], wherein the amount of hexanal contained in the formula when the produced formula is stored at room temperature for 2 months is 0.6 ppm or less.

Furthermore, the present invention also includes the following [6] to [29].
[6]
A step of mixing copper and whey protein in a liquid to prepare a copper-bound whey protein solution having a copper binding rate of 80% or more;
A step of preparing a liquid formula by mixing the prepared copper-bound whey protein solution and a formula milk raw material containing proteins, fats and oils containing unsaturated fatty acids, sugars, vitamins, and minerals in a liquid. ,
A step of heat sterilizing the prepared liquid formula,
A process of producing liquid milk powder by drying the heat-sterilized liquid formula;
The manufacturing method of formula milk powder containing this.
[7]
The method according to [6], wherein the step of preparing the copper-bound whey protein solution is performed by mixing an aqueous copper solution and a whey protein solution.
[8]
The method according to [7], wherein the whey protein solution is a whey protein solution having a concentration of 0.7 to 8.0% by mass in terms of a final concentration after mixing with an aqueous copper solution. .
[9]
The step of preparing a copper-bound whey protein solution comprises:
The method according to any one of [6] to [8], wherein the whey protein is mixed with copper and whey protein at a ratio of 60 parts by mass or more with respect to 1 part by mass of copper.
[10]
The step of preparing liquid formula is
The method according to any one of [6] to [9], wherein the method is performed by mixing the prepared copper-bound whey protein solution and the solution of the raw milk material.
[11]
The method according to any one of [6] to [10], wherein the copper is one or more selected from the group consisting of copper sulfate, copper gluconate, copper citrate, copper chloride, and copper nitrate.
[12]
The method according to any one of [6] to [11], wherein the prepared formula milk has a peroxide value of 0.8 meq / kg or less when stored for 2 months at room temperature.
[13]
The method according to any one of [6] to [12], wherein the amount of hexanal contained in the prepared formula when the prepared formula is stored at room temperature for 2 months is 0.6 ppm or less.
[14]
The method according to any one of [6] to [13], wherein in the step of preparing liquid formula milk, a formula milk raw material sterilized in advance is used as the formula milk raw material.
[15]
The step of heat sterilizing the prepared liquid formula and the step of drying the heat sterilized liquid formula and producing the prepared powdered milk,
Heating the prepared liquid formula and drying it to produce formula milk;
The method according to any one of [6] to [14], wherein
[16]
Formula milk powder manufactured by the method in any one of [6]-[15].
[17]
The prepared powdered milk according to [16], wherein the produced powdered milk has a peroxide value of 0.8 meq / kg or less when stored for two months at room temperature.
[18]
The prepared powdered milk according to any one of [16] to [17], wherein the amount of hexanal contained in the prepared powdered milk when the prepared powdered milk is stored at room temperature for 2 months is 0.6 ppm or less.
[19]
A step of mixing copper and whey protein in a liquid to prepare a copper-bound whey protein solution having a copper binding rate of 80% or more;
A step of preparing a liquid formula by mixing the prepared copper-bound whey protein solution and a formula milk raw material containing proteins, fats and oils containing unsaturated fatty acids, sugars, vitamins, and minerals in a liquid. ,
A step of heat sterilizing the prepared liquid formula,
A method for producing liquid formula, comprising:
[20]
The method according to [19], wherein the step of preparing the copper-bound whey protein solution is performed by mixing an aqueous copper solution and a whey protein solution.
[21]
[19] to [20], wherein the whey protein solution is a whey protein solution having a concentration of 0.7 to 8.0% by mass in terms of the final concentration after mixing with the copper aqueous solution. The method in any one of.
[22]
The step of preparing a copper-bound whey protein solution comprises:
The method according to any one of [19] to [21], wherein the whey protein is mixed with copper and whey protein at a ratio of 60 parts by mass or more with respect to 1 part by mass of copper.
[23]
The step of preparing liquid formula is
The method according to any one of [19] to [22], wherein the method is performed by mixing the prepared copper-bound whey protein solution and the solution of the raw milk material.
[24]
The method according to any one of [19] to [23], wherein the copper is one or more selected from the group consisting of copper sulfate, copper gluconate, copper citrate, copper chloride, and copper nitrate.
[25]
[19] A liquid formula produced by the method according to any one of [24].
[26]
Use of a copper-bound whey protein solution prepared by mixing copper and whey protein in a liquid and having a copper binding rate of 80% or more as a source of copper element in liquid formula milk.
[27]
A copper element additive for liquid preparation milk comprising a copper binding whey protein solution having a copper binding rate of 80% or more prepared by mixing copper and whey protein in a liquid.
[28]
A step of mixing copper and whey protein in a liquid to prepare a copper-bound whey protein solution having a copper binding rate of 80% or more;
The manufacturing method of the copper element additive for liquid formula dairy milk containing.
[29]
[28] A liquid elemental copper element additive produced by the method according to [28].

The effects produced by the present invention are as follows.
(1) In the manufacture of formulas containing copper and unsaturated fatty acids, it is possible to effectively suppress fatty acid formation in formula preparation liquids in the production stage and formulas after production.
(2) Since oxidation is suppressed even when copper and an unsaturated fatty acid are mixed, the formula can be easily produced with all components added thereto, so that the process is not complicated.
(3) Whey protein used together with copper is a milk-derived component, and since it is a raw material that has been conventionally added to formula milk, it is safe in terms of safety and is a simple method.
(4) Since the flavor component hexanal that increases with the oxidation of the formula milk can be suppressed, it is possible to maintain a good flavor and to extend the storage period.
(5) It is a simple method and can be widely applied to the production of foods and drinks, feeds, pharmaceuticals and the like containing copper.
(6) Liquid formula milk to which copper element has been added, which has been difficult to manufacture as a stable product by a widely used conventional manufacturing method, can be manufactured.
(7) If the copper-bound whey protein solution of the present invention is used, it can be mixed in a liquid with a formula milk raw material containing components other than copper element, so that it can be easily and reliably uniform. Mixing is possible.

  Next, a preferred embodiment of the present invention will be described in detail. However, the present invention is not limited to the following preferred embodiments, and can be freely changed within the scope of the present invention. In the present specification, percentages are expressed by mass unless otherwise specified.

<1> Formula milk and its raw material [Liquid formula]
The liquid formula of the present invention is produced using raw milk, milk, special milk, or a milk raw material produced from these raw materials as a main raw material, and further added with nutrients necessary for infants. However, any of them is in a liquid form.
Moreover, as an aspect of liquid formula milk, there exists a liquid type | formula which mix | blended various nutrients, such as minerals, vitamins, and protein, and was close to human milk. The liquid formula of the present invention includes any of these definitions.
The liquid formula of the present invention includes formulas for infants, formulas for infants (follow-up milk), formulas for pregnant and lactating women, nutrition formulas for adults, nutrition formulas for the elderly, etc. It is.

  Moreover, the liquid formula milk of this invention can manufacture the formula milk powder of this invention by drying this. Liquid formula milk containing elemental copper as trace metal element components and fats and oils containing unsaturated fatty acids can be produced as a stable product for the first time by the present invention. The liquid formula of the present invention is useful as an intermediate product for producing the formula of the present invention, and at the same time is also useful as a final product.

[Formulated milk powder]
Prepared powdered milk is required for infants by processing raw milk, milk, special milk, or foods made from these raw materials, or using them as the main ingredients in the ministerial ordinance on milk and dairy product component specifications (Ministerial Ordinance for Milk, etc.). Included are those defined as “powdered with nutrients”.
In general, the formula powdered milk is obtained by blending nutritional components such as various minerals, vitamins, proteins, and the like, closer to human milk, and further processed into a powder form. The formula of the present invention includes any of these definitions.
The formula in the present invention includes formulas for infants, infant formulas (follow-up milk), maternal and lactation formulas, nutritional powders for adults, nutritional powders for the elderly, and the like.

[Formulated milk]
In the present invention, liquid formula milk and formula milk powder may be referred to as formula milk.

[copper]
In this specification, unless otherwise specified, copper means copper element as a trace metal component as contained in formula milk. And as such copper, specifically, it is preferable to use a copper compound.
As the copper compound, for example, a salt containing copper (a copper salt) can be used, and a water-soluble salt can be preferably used. As such a copper salt, for example, copper sulfate, copper gluconate, copper citrate, copper chloride, copper nitrate and the like can be used. An aqueous solution containing such a water-soluble copper compound (for example, a copper salt) and containing copper ions may be simply referred to as an aqueous copper solution in this specification.
Only one type of copper compound may be used as the “copper” of the present invention, or a mixture of two or more types may be used.

[Whey protein]
The “whey protein” of the present invention means “whey protein” itself, but in addition to the use of purified high-purity “whey protein”, low-purity components other than whey protein can be used. It can also be used.

The “milk raw material” used for producing the whey protein raw material can be used as an alternative to the whey protein as it is. The “milk raw material” in this case can be referred to as “whey protein raw material”.
That is, as the whey protein raw material of the present invention, ordinary dairy products containing whey protein such as raw milk, skim milk, whole milk powder, and skim milk can be used.

  As a method for purifying whey protein, a method of removing casein and milk fat by adding rennet or the like to milk or skim milk powder, a method of further processing from the above steps by gel filtration, ultrafiltration, ion exchange, etc. There are whey protein concentrates and whey protein isolates obtained by these methods. A whey protein material such as a commercially available whey protein concentrate (hereinafter sometimes referred to as WPC) or a whey protein isolate (hereinafter sometimes referred to as WPI) may be used. it can.

  In general, whey protein includes β-lactoglobulin, α-lactalbumin, serum albumin, immunoglobulin, lactoferrin, proteose peptone, etc., but also in the “whey protein” used in the present invention. These components may be contained.

The whey protein raw material used as the “whey protein” of the present invention is preferably an aqueous solution.
Moreover, only 1 type may be used for the whey protein raw material used as "whey protein" of this invention, and 2 or more types may be mixed and used for it.

[protein]
As the protein of the present invention, any protein can be used as long as it can be used as a raw material of formula milk. In addition to milk-derived proteins such as skim milk powder, whole milk powder, casein, whey protein, and hydrolysates thereof, soy protein, etc. Can be used.

[Unsaturated fatty acids]
Examples of the unsaturated fatty acid of the present invention include docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), linoleic acid, linolenic acid, and arachidonic acid. The unsaturated fatty acid of the present invention is not particularly limited as long as it is added to food and drink.

[Oils and fats]
The fats and oils of the present invention are animal fats and oils such as milk fat, fish oil and egg yolk oil obtained from cattle, buffalo, goats and donkeys, and vegetable oils and fats such as soybean oil, corn oil, sesame oil, sesame oil and rapeseed oil. In addition, any of fats and oils obtained by culturing microorganisms can be included.

[Sugar]
As the saccharide of the present invention, lactose, dextrin, starch, raffinose, lactulose, trehalose and the like can be used.

[Vitamins]
As the vitamins of the present invention, water-soluble vitamins such as vitamin B group and vitamin C, and fat-soluble vitamins such as vitamin A, vitamin D and vitamin E can be used.

[Minerals]
As the minerals of the present invention, sodium, potassium, calcium, iron, zinc, manganese salts can be used, and preferably sodium chloride, potassium chloride, calcium carbonate, ferric pyrophosphate, zinc sulfate, sulfuric acid It can be blended in the form of manganese or the like. In general, copper is included as minerals added to formula milk, but in the present invention, copper is added in the form of copper-bound whey protein, so copper is not added as minerals. Things are used. Copper here is a copper element as a component, and specifically refers to a copper compound. However, it is also within the scope of the present invention to add and use copper elements as minerals within the range where the effects of the present invention are exhibited.

<2> Manufacturing method of formula milk In one mode of suitable implementation of the present invention, formula milk (prepared milk powder and liquid formula milk) can be manufactured including the process illustrated below.

(1) “Step of preparing a copper-bound whey protein solution”
In the method for producing formula milk of the present invention, a copper-bound whey protein prepared by previously combining copper used as a raw material of formula milk with whey protein is prepared, and this is used as a copper source for producing formula milk. To do. This step is the most characteristic step of the present invention.
When the copper-bound whey protein prepared in this way is mixed with other raw milk ingredients containing fats and oils, the oxidation of fats and oils that would otherwise occur during the milk production process, which would otherwise have been caused by the addition of metals However, it is possible to produce a formula that is effectively suppressed, has a good flavor and can be stored for a long time.
That is, the step of preparing the copper-bound whey protein solution is a step of preparing a copper-bound whey protein solution by mixing copper and whey protein in the liquid, and the copper in the mass of the added copper compound. In this step, the percentage of the mass of copper bound to whey protein relative to the mass of whey is expressed as a percentage (hereinafter referred to as “copper binding ratio”) of 80% or more. Thus, the effect of this invention is suitably exhibited because a copper bond rate shall be 80% or more. The copper bond ratio is preferably 80% or more, more preferably 90% or more, and particularly preferably 94% or more. A larger copper bond ratio is preferable from the viewpoint of suppressing oxidation.
“Mixing copper and whey protein in a liquid” means mixing a copper compound solution and a whey protein solution. In a preferred embodiment, this step can be performed by mixing an aqueous solution of a copper salt and a whey protein solution.

  In the step of preparing the copper-bound whey protein solution, the mixed solution containing copper and whey protein is held at a temperature of 20 to 125 ° C. for 1 to 2 seconds to bind the copper and whey protein. It is preferred to prepare a copper-bound whey protein solution. In a preferred embodiment, it is preferable to prepare a copper-bound whey protein solution by heating for 10 minutes to 5 seconds at a temperature of 80 to 100 ° C. to bind copper and whey protein. In addition, when heating at 100 degreeC or more, it is preferable to heat under pressure using a plate sterilizer.

  In the step of preparing the copper-bound whey protein solution of the present invention, the concentration of whey protein when mixing copper and whey protein in the liquid is converted to the final concentration after mixing with the aqueous copper solution. The range is preferably 0.7 to 8.0% by mass, more preferably 1.0 to 8.0% by mass, still more preferably 1.0 to 5.0% by mass, and still more preferably 1. The concentration is preferably in the range of 0 to 4.5% by mass, more preferably in the range of 2.0 to 4.5% by mass, and still more preferably in the range of 2.25 to 4.5% by mass.

  On the other hand, if the copper concentration is within the range where the copper binding rate is 80% (percentage) or more in the “step of preparing a copper binding whey protein solution” in the production method of the present invention, the set whey protein is used. Depending on the concentration, it can be appropriately changed.

  In the “step of preparing a copper-bound whey protein solution” in the production method of the present invention, the concentration of whey protein and the concentration of copper when mixing copper and whey protein in the liquid are as described above. Furthermore, as a mixing ratio of the mass of copper and the mass of whey protein, the ratio of the mass of copper and the mass of whey protein is preferably 60 parts by mass or more of whey protein with respect to 1 part by mass of copper. . In other words, the mass ratio of copper to whey protein (copper: whey protein) is preferably copper: whey protein = 1: ≧ 60, preferably 1: 60-1: 3000. 1: 60-1: 1000, preferably 1: 60-1: 500, preferably 1: 60-1: 300, 1: 60-1: 150 Is preferably 1:90 to 1: 150, and preferably 1:90 to 1: 113.

  The copper-bound whey protein solution prepared in this step is a state in which the copper ions present in the solution are bound to the whey protein (the state in which almost no free copper ions are present: the proportion of free copper ions is less than 20%). This effectively suppresses oxidation that should be promoted by copper.

The copper-bound whey protein in the present invention means a copper-bound whey protein. Specifically, an aqueous solution of copper-bound whey protein can be used, and the copper-bound whey protein aqueous solution can be used. In this case, unbound copper and whey protein may be present in a range satisfying the above copper binding rate of 80% or more. Therefore, although it is estimated that it is an aspect of any one of a) to d) below, any aspect can be handled as the copper-bound whey protein of the present invention. The copper described in (hereinafter a) to d) specifically means copper ions generated from, for example, a copper compound or a copper salt. )
a) Copper-bound whey protein + water
b) Copper-bound whey protein + water + copper
c) Copper-bound whey protein + water + whey protein
d) Copper-bound whey protein + water + copper + whey protein

In the present invention, the copper binding rate is a ratio (percentage (%)) of the mass of copper combined with the whey protein to the mass of added copper, and can be defined as follows. It can be calculated by the method.
Since the whey protein to which copper is bound forms a card, precipitation occurs when it is centrifuged at 30,000 rpm for 1 hour using a centrifuge. In the supernatant of the copper-bound whey protein solution of the present invention, copper (copper ions) released without binding to the whey protein is present in a proportion of less than 20% of the total copper. Therefore, the mass obtained by subtracting the mass of copper in the supernatant of the copper-bound whey protein solution from the mass of copper used for binding to whey protein is converted as the mass of copper bound to whey protein. Since it can do, the copper bond rate (%) of this invention was computed by the following formula | equation.
Copper binding rate (%) = [mass of added copper−copper mass in a copper-bound whey protein solution supernatant] / [mass of added copper] × 100

  [Mass of added copper] and [Mass of copper in the supernatant of copper-bound whey protein solution] are respectively the values of [copper solution before being added to whey protein] and [copper-bound whey protein solution]. For the clean solution], the mass can be calculated by measuring the absorbance of copper using an atomic absorption spectrophotometer (for example, using Seiko Denshi Kogyo Co., Ltd.).

  The copper-bound whey protein solution prepared according to the above embodiment can be used in the next step of preparing formula (liquid formula), but not directly in the process of preparing liquid formula. First, dry the copper-bound whey protein solution to produce a copper-bound whey protein powder, dissolve in dissolved water at the time of use, prepare the copper-bound whey protein solution again, and prepare the liquid formula You may use for a process. In addition, when using a copper bond whey protein solution for manufacture of formula milk, since the card | curd is formed in the solution, it is preferable to stir etc. and to disperse | distribute well.

  In other words, the copper-bound whey protein solution of the present invention is integrated with whey protein that incorporates copper, so that the binding state is stable even after repeated drying and dissolution. The state in which copper is bound to the whey protein can be maintained by mixing with the raw material, heating, spray drying, re-dissolution, and the like.

  In addition, the present invention has been achieved by finding that, by treating only copper among various metal elements to obtain a copper-bound whey protein, it is possible to realize a sufficient oxidation-inhibiting effect. However, a process similar to the process of preparing the copper-bound whey protein solution can be performed on metal components other than copper. For example, in the process of preparing a copper-bound whey protein solution, an iron-bound whey protein or a zinc-bound whey protein is prepared using an iron compound or a zinc compound instead of the copper compound used as copper. You can also. That is, iron-binding whey proteins can be prepared using iron compounds such as iron sulfate, iron chloride, and iron gluconate as iron, and zinc compounds such as zinc sulfate and zinc gluconate can be used as zinc. It can be used to prepare zinc-bound whey protein. The iron-bound whey protein or zinc-bound whey protein prepared in this way is used for adding metal to liquid formula milk together with the copper-bound whey protein, and further exhibits the oxidation-suppressing effect of the present invention. You can be sure.

  In general, metals contained in formula milk, especially transition metals, have a catalytic reaction to oxidize lipids, and other metals using the technology of copper uptake by whey protein as in the present invention. When applied to, it is possible to produce a formula that has a better flavor and can be stored for a long time.

(2) “Process for preparing liquid formula”
The copper-bound whey protein solution prepared in the above step is subsequently mixed with the raw material of the prepared milk in the “step of producing liquid formula”, and heat sterilized to produce liquid formula. The “process for producing liquid formula” according to the present invention means a copper-bound whey protein solution prepared in “a process for preparing a copper-bound whey protein solution”, proteins, fats and oils containing unsaturated fatty acids, saccharides, This is a step of preparing a liquid formula by mixing with a formula milk raw material consisting of vitamins and minerals (however, the added minerals do not include copper alone and a compound) and sterilization by heating.

  The ingredients of the formula milk mixed with the copper-bound whey protein solution include protein, fats and oils containing unsaturated fatty acids, saccharides, vitamins, and minerals (however, the added minerals do not contain copper element) ), Etc., and before mixing with the copper-bound whey protein solution, it is preferable to add a predetermined amount to water, raw milk, skim milk, etc., and heat it appropriately to dissolve it.

  In addition, the fats and oils which are a part of raw material of formula milk are previously heat-melted, and are added to the raw material solution of formula milk prepared above. It is preferable that the raw material solution of the formula milk to which fats and oils are added is homogenized by a homogenizer. The fats and oils can be mixed with a solution in which a part of the raw material of the formula is dissolved, and once homogenized, the remaining raw material of the formula is added to complete the raw material solution of the formula. In addition, the raw material solution of the formula milk (prepared milk material) can be heat sterilized before mixing with the copper-bound whey protein solution.

(3) “Process of heat sterilizing liquid formula”
Liquid formula milk mixed and prepared as described above is sterilized by heating at 75 to 150 ° C. using a plate sterilizer or the like. Subsequent to the heat sterilization step, a homogenization step for adjusting the fat globules in the liquid to a uniform size and obtaining a good emulsified state can be added.

  The liquid formula of the present invention has remarkably excellent characteristics that the oxidation promoting action of unsaturated fatty acids by copper is not exhibited even when heat sterilized in the state where unsaturated fatty acids and copper coexist in the solution. Have.

The heat-sterilized and produced liquid formula is an intermediate product that can be dried and used to produce formula milk, while at the same time being the final product. That is, the liquid formula milk produced by heat sterilization is transferred to a filling machine in a sanitary manner, and can be directly filled into a container such as paper, plastic, or aluminum to obtain a product.
The liquid formula of the present invention preferably contains 1 to 200 μg of copper per 100 ml of formula.

The copper contained in the formula milk is the total amount of copper in the formula milk produced by the method of the present invention. In addition to the copper added as a copper-bound whey protein solution, the formula milk such as protein and minerals Copper as a minor component of the raw material is also included. The liquid formula of the present invention preferably has a concentration suitable for drinking as it is. This is because contamination such as bacterial contamination due to water during use can be prevented, and it can be ingested hygienically.
Therefore, it is preferable that the concentration of the liquid formula of the present invention is adjusted before heat sterilization, or it is hygienically adjusted after heat sterilization.
The liquid formula obtained in this way has the effect of the present invention that the oxidation of fats and oils is sufficiently suppressed, has a good flavor, and can be stored for a long period of time.

(4) “Process for producing liquid formula by drying liquid formula”
The liquid formula prepared by mixing the copper-bound whey protein solution of the present invention and the formula milk raw material can be sterilized by heating and then dried to produce powdered formula (prepared milk powder). Heat sterilization and drying may be performed in one step. In the step of drying, spray drying with hot air or freeze drying can be performed. Spray drying with hot air is preferable because it involves heating and exhibits a certain bactericidal action. The obtained powder can be filled into a product without newly adding components. The formula powdered milk of the present invention is a powdered milk powder (prepared powdered milk), the oxidation of fats and oils is sufficiently suppressed, the flavor is good, and the effect of the present invention that it can be stored for a long time is sufficiently exhibited. It has become.

<3> About Emulsified Liquid As described in Test Example 6 of the present invention, it is possible to examine the effect of inhibiting oxidation in prepared milk using an emulsified liquid instead of the prepared raw milk solution defined above. is there. The emulsion used in the present invention can be exemplified by an emulsion obtained by mixing milk protein and fats and homogenizing, and testing in the emulsion allows oxidation in prepared milk. An effect equivalent to the suppression effect can be quickly measured and confirmed.

<4> About Oxidation Inhibition and Aroma Component Reduction Effect The prepared milk obtained by the production method of the present invention is characterized in that the oxidation of fats and oils is effectively suppressed and specific aroma components are reduced. is there. The prepared milk produced by the production method of the present invention is obtained by the peroxide value (POV) representing the degree of oxidation, the quantification of hexanal which is a kind of aroma component, and the sensory evaluation based on the flavor test. The effect of the formula can be evaluated.
The formula of the present invention can be similarly evaluated by the above-described evaluation method, regardless of whether the formula is liquid formula (liquid formula) or powdered formula (prepared formula).

(1) Peroxide value (POV)
As a method for examining the degree of oxidation of fats and oils or fat-containing foods, a peroxide value (POV) or an acid value (AV) is often used. In particular, the peroxide value (POV) can be applied as an index for measuring the degree of oxidation of formula milk produced by the production method of the present invention.

  POV is a method for measuring the content of hydroperoxide produced by oxidation of fats and oils by an iodometric titration method, and is widely used as an index for determining the degree of acidity in the initial stage. Meq / kg is used as a unit, and the larger the number, the more the oxidation is advanced.

  The POV measurement was tested according to the iodometric titration method (edited by the Food Analytical Society of Japan, “Food Analysis Method”, page 552, Korin, 1982), which is the official method of the Japan Oil Chemical Association. can do.

  For example, about 10 g of fats and oils are extracted from a stored sample and weighed accurately. This oil is put into a stoppered Erlenmeyer flask and dissolved by adding 35 ml of chloroform / glacial acetic acid mixed solution (2: 3). Next, add 1 ml of saturated potassium iodide solution while passing air through the flask through nitrogen gas or carbon dioxide. Immediately plug and mix for about 1 minute. Then, with starch test solution as an indicator, 0.01N sodium thiosulfate solution. Titrate. Separately, perform a blank test and correct it.

The peroxide value is determined by the following formula.
Peroxide value (meq / kg) = [(a × F) / S] × 10
Where S: Amount of sample collected (g)
a: Consumption of 0.01N sodium thiosulfate solution (ml)
F: Potency of 0.01N sodium thiosulfate solution

Since the POV value is also affected by the storage environment (temperature, humidity, light, oxygen) of the sample, the POV value of formula milk produced by the production method of the present invention takes these into account. It is desirable to be.
That is, the powdered milk produced by the production method of the present invention is sealed with an aluminum bag or the like, and has a peroxide value of 1.0 meq / kg or less when stored for 2 months at room temperature under light shielding. Is preferably 0.8 meq / kg or less, and most preferably 0.78 meq / kg or less.

(2) Determination of aroma components In the present invention, hexanal, an aroma component that increases as the oxidation of fats and oils progresses, can be measured and evaluated as the degree of oxidation. Hexanal can be measured as an aroma component generated when a powdered milk sample is dissolved in temperature-adjusted water, or as an aroma component generated from a solution such as liquid formula milk. It can be analyzed with a tomograph mass spectrometer (GC / MS) or the like.

The hexanal amount of the present invention is a value obtained by quantifying the area on the measured chromatogram and further quantifying it by an internal standard method. In measuring the amount of hexanal, an internal standard sample was added for each measurement, and the area was measured to prevent an error in the absolute value.
The analysis conditions of the aroma component can be performed under the following conditions.

[measuring equipment]
GC: AGILENT, 6890 type MS: AGILENT, 5973 type Column: INNOWAX (trade name, manufactured by AGILENT)
Film thickness: 0.5 μm Length: 30 m Diameter: 0.25 mm
SPME fiber: manufactured by SUPELCO [Method of separating and concentrating aroma components]
Solid phase microextraction method (SPME): 50 ° C., 30 minutes head space method [measurement conditions]
-GC inlet temperature: 265 ° C
・ Gas flow rate: 1.2 ml / min ・ Helium gas oven temperature rising condition: 40 ° C., 2 min, 4 ° C./min (up to 120 min), 6 ° C./min (up to 240 min), 10 min hold ・ MS measurement mode : Scan 2.32 (SCAN / sec)

  The prepared milk powder produced by the production method of the present invention is preferably sealed with an aluminum bag or the like, and the amount of hexanal in the prepared milk powder when stored for 2 months at room temperature under light shielding is preferably 1.1 ppm or less. More preferably, it is 0.0 ppm or less, more preferably 0.6 ppm or less, and most preferably 0.55 ppm or less.

(3) Sensory evaluation test The formula milk powder manufactured with the manufacturing method of this invention can be evaluated with the following method. That is, for a prepared milk powder that is sealed with an aluminum bag or the like and stored for two months at room temperature under light shielding, a sample of the prepared milk powder becomes a solid content of 13.0 g / 100 ml by a plurality of sensory evaluation panelists. Thus, it is possible to evaluate the flavor by preparing a sample solution by dissolving in hot water and performing a sensory evaluation test.

For the sensory evaluation test, the flavor can be evaluated in four stages: “best” (3 points), “good” (2 points), “slightly bad” (1 point), and “bad” (0 points). .
In the overall evaluation of the sensory evaluation test, the average score of the panel taste test was evaluated as 3-2.5 points as “best”: ◎, and 2.5-1.5 points as “good”: ○. , 1.5 to 0.5 points can be evaluated as “slightly defective”: Δ, and 0.5 to 0 points can be evaluated as “bad”: x.

EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited to a following example.
[Example 1]
(1) Copper sulfate (Tonda Pharmaceutical Co., Ltd., copper content 25.3% by mass) was dissolved in water to prepare a 0.84% by mass copper solution as copper. A whey protein concentrate (WPC: manufactured by Mirai) was dissolved in water so that the concentration of whey protein was 4.3% by mass to prepare a whey protein solution. Copper solution and whey protein solution were mixed at a weight ratio of 6:94 (final copper concentration: 0.05 mass%, final whey protein concentration: 4.0 mass%), and the mixed solution was at 80 ° C. for 10 minutes. It heat-processed and then cooled to 10 degrees C or less, and the copper bond whey protein solution was prepared.
In addition, it confirmed that the copper bond rate in the copper bond whey protein solution prepared above was 86.9%.

(2) 1160 g of skim milk (Morinaga Milk Industry), 500 g of desalted whey powder (Domo), 59 g of lactose (Mirai), and 52 g of dextrin (Toyo Seika) are dissolved in 5471 g of water in advance with caustic soda. It was mixed with 143 g of 10% casein solution which had been dissolved and deodorized. This was further mixed with 240 g of fish oil blended prepared fat (manufactured by NOF. Fish oil containing 1.5 g per 100 g of fat and oil) and 33 g of unsalted butter (manufactured by Morinaga Milk Industry), and homogenized under a pressure condition of 15 MPa.
Subsequently, 307 mg of ferric pyrophosphate (manufactured by Tomita Pharmaceutical) and 104 mg of zinc sulfate (manufactured by Tomita Pharmaceutical) are dissolved in 50 g of water, and this is cooled to 10 ° C. or less to prepare a mineral solution. The prepared milk raw material solution was prepared by adding to the previously prepared mixed solution.

(3) The copper-bound whey protein solution prepared in (1) above and the prepared milk raw material solution prepared in (2) were mixed at a ratio of 1: 1200, then sterilized at 125 ° C. for 2 seconds, and 15 MPa The mixture was homogenized under pressure conditions to prepare 7000 g of liquid formula milk.
The produced liquid formula had good appearance and flavor, and the peroxide value was less than 0.5 meq / kg.

[Example 2]
(1) Copper sulfate (Tonda Pharmaceutical Co., Ltd., copper content 25.3% by mass) was dissolved in water to prepare a 0.84% by mass copper solution as copper. A whey protein concentrate (WPC: manufactured by Mirai) was dissolved in water so that the concentration of whey protein was 4.3% by mass to prepare a whey protein solution. Copper solution and whey protein solution were mixed at 6:94 (final copper concentration: 0.05% by mass, final whey protein concentration: 4.0% by mass), and the mixed solution was heated at 80 ° C. for 10 minutes. Then, it was cooled to 10 ° C. or lower to prepare a copper-bound whey protein solution.
In addition, it confirmed that the copper bond rate in the copper bond whey protein solution prepared above was 86.9%.

(2) 1160 g of skim milk (Morinaga Milk Industry), 500 g of desalted whey powder (Domo), 59 g of lactose (Mirai) and 52 g of dextrin (Toyo Seimitsu) are dissolved in 2380 g of water and pre-loaded with caustic soda. It was mixed with 143 g of 10% casein solution which had been dissolved and deodorized. This was further mixed with 240 g of fish oil blended prepared fat (manufactured by NOF. Fish oil containing 1.5 g per 100 g of fat and oil) and 33 g of unsalted butter (manufactured by Morinaga Milk Industry) and homogenized under a pressure condition of 15 MPa, then 125 Sterilized at 2 ° C. for 2 seconds, homogenized under a pressure condition of 15 MPa, and then concentrated to a solid content of 50% to prepare a concentrated solution.
Subsequently, 307 mg of ferric pyrophosphate (manufactured by Tomita Pharmaceutical) and 104 mg of zinc sulfate (manufactured by Tomita Pharmaceutical) are dissolved in 50 g of water, and this is cooled to 10 ° C. or less to prepare a mineral solution. The prepared powdered milk raw material solution was prepared by adding to the previously prepared concentrated solution.

(3) The copper-bound whey protein solution prepared in (1) and the prepared milk raw material solution prepared in (2) were mixed at a ratio of 1: 320.

(4) The mixed solution of (3) was spray-dried with hot air by a conventional method to obtain about 900 g of prepared milk powder.
In the produced prepared milk powder, fragrance (oxidation odor) components such as hexanal were hardly confirmed, and the peroxide value was less than 0.5 meq / kg. Moreover, even if the prepared powdered milk is sealed in an aluminum bag and stored at room temperature under light shielding for 2 months, almost no aroma (oxidation odor) component such as hexanal is confirmed, and the peroxide value is 0.8 meq / kg. The flavor was good.

Next, the present invention will be described in detail with reference to test examples. In this test example, as long as there is no notice, the formula milk used the formula milk.
[Test Example 1]
This test was performed in order to evaluate the influence on the flavor of formula milk by the difference in the copper binding rate in the copper binding whey protein solution.

(1) Preparation of sample Copper sulfate (made by Iwata Pharmaceutical Co., Ltd., copper content 25.3%) was dissolved in water to prepare a 0.84 mass% copper solution as copper. A whey protein concentrate (WPC: manufactured by Mirai) was dissolved in water so that the whey protein concentration was 4.8% by mass to prepare a whey protein solution.
By measuring a certain amount of copper solution and changing the ratio of whey protein added to copper in the copper solution, the copper binding rate was 97.2%, 94.7%, 80.0%, respectively. 67.4%, 42.0%, and 33.6% copper-bound whey protein solutions were prepared.
Furthermore, prepared milk powder produced by the same method as (2) to (4) in Example 2 was used as a test sample.

(2) Test method
a) Measurement of copper binding rate The mass (copper content) of copper contained in the copper sulfate solution used to prepare the copper-bound whey protein solution was measured with an atomic absorption spectrophotometer (Seiko Denshi Kogyo Co., Ltd .: SAS7500 type). did.
Further, the prepared copper-bound whey protein solution was centrifuged at 30,000 rpm for 1 hour using a centrifuge (manufactured by Hitachi Koki Co., Ltd.), then the supernatant was recovered, and the copper content in the supernatant was measured by atomic absorption. Measured with a spectrophotometer.
The copper mass was calculated based on the measured absorbance (absorbance at 324.75 nm) and the calibration curve using the copper standard solution, and the copper binding rate was determined by the following formula.
Copper binding rate (%) = [copper mass−copper mass in the copper-bound whey protein solution supernatant] / [copper mass] × 100

b) Sensory evaluation test Prepared powdered milk produced using copper-bound whey protein solutions having different copper binding rates was sealed with an aluminum bag and stored at room temperature for 2 months under light shielding. A sample after storage was collected and dissolved in hot water so that the solid content of the sample was 13.0 g / 100 ml to prepare a test sample solution, and the sensory evaluation test was performed on the flavor by six sensory evaluation panelists. . For the flavor (overall evaluation including evaluation of oxidation odor) test, there are four levels: “best” (3 points), “good” (2 points), “slightly bad” (1 point), and “bad” (0 points). It was evaluated with.
In addition, the overall evaluation of the sensory evaluation test is as follows. The average score of the panel taste test is evaluated as 3-2.5 points as “best”: ◎, and 2.5-1.5 points as “good”: ○. Evaluation was made, and 1.5 to 0.5 points were evaluated as “slightly bad”: Δ, and 0.5 to 0 points were evaluated as “bad”: x.

(3) Test results The results of this test are as shown in Table 1. Table 1 is a table showing sensory evaluation of prepared milk powder produced using a copper-bound whey protein solution having each copper binding rate.
As a result, the prepared milk powder produced using a copper-bound whey protein solution having a copper binding rate of 80% or more was evaluated as “best” and “good” in the overall evaluation of the sensory evaluation test.
That is, it is clear from this test that it is possible to produce a prepared powdered milk having a good taste by using a copper-bound whey protein solution used in the method for producing a prepared powdered milk of the present invention having a copper binding rate of 80% or more. became.

[Test Example 2]
This test was conducted to measure the whey protein concentration and the copper binding rate at each concentration when preparing a copper-bound whey protein solution.

(1) Sample preparation The sample of this test was converted to the final concentration (final whey protein concentration) after adding and mixing the whey protein concentration in the step (1) of Example 1 above. The same concentration except that the concentration was 0.68% by mass, 2.25% by mass, 4.0% by mass, 4.5% by mass, 8.0% by mass, and 9.0% by mass, respectively. A copper-bound whey protein solution was prepared by the method as a test sample.

(2) Test method (2) Test method of Test Example 1, a) Copper bond rate was calculated in the same manner as the measurement of copper bond rate.

(3) Test results The results of this test are as shown in Table 2. Table 2 is a table | surface which shows the relationship between the whey protein density | concentration at the time of preparing a copper bond whey protein solution, and a copper bond rate.
As a result, when the whey protein concentration in the prepared copper-bound whey protein solution is 2.25% by mass to 8.0% by mass in terms of the final whey protein concentration, the copper binding rate is 80% or more. It became clear to show the value.
The sample prepared by converting the whey protein concentration to the final whey protein concentration to 0.68% by mass was based on the whey protein concentration in the example of Patent Document 1, but the copper binding rate was 28.8%. Met. This result indicates that the effect of the present invention is not exhibited when the whey protein concentration is too low.
On the other hand, when the copper-bound whey protein is prepared so that the whey protein concentration is 9.0% by mass in terms of the final whey protein concentration, the whey protein is gelated by heating at 80 ° C. for 10 minutes. As a result, a copper-bound whey protein solution that could be used in the present invention was not prepared. Therefore, the copper bond rate could not be measured.

[Test Example 3]
This test was conducted to examine the relationship between the copper-to-whey protein mass ratio and the copper binding rate when a copper-bound whey protein solution was prepared.

(1) Preparation of sample In the process of Example 1 (1), the sample of this test was 4.5% by mass in terms of the whey protein concentration in the copper-bound whey protein solution converted to the final whey protein concentration. A copper-bound whey protein solution was prepared in the same manner except that the whey protein was 45 to 150 parts by mass when the mass ratio of copper to whey protein was 1 part by mass of copper. This was used as a test sample.

(2) Test method (2) Test method of Test Example 1, a) Copper bond rate was calculated in the same manner as the measurement of copper bond rate.

(3) Test results The results of this test are as shown in Table 3. Table 3 shows the copper concentration (copper concentration converted to the final concentration after adding and mixing the copper concentration to be added) when preparing the copper-bound whey protein solution, the mass ratio of copper and whey protein, and copper It is a table | surface which shows a coupling | bonding rate.
As a result, when the whey protein was 45 parts by mass with respect to 1 part by mass of copper, the copper binding rate was 67.4%. This is presumed that the mass of whey protein relative to the mass of copper was not sufficient.
On the other hand, when the mass ratio of copper to whey protein was within the range of 60 to 150 parts by mass of whey protein with respect to 1 part by mass of copper, the copper binding rate was 80% or more.
From the above results, in order to prepare the copper-bound whey protein solution of the present invention, the whey protein is preferably 60 to 150 parts by mass with respect to 1 part by mass of copper in the mass ratio of copper to whey protein.

  In addition, in mass ratio of copper and whey protein, when whey protein is 150 mass parts or more with respect to 1 mass part of copper, that is, by mass ratio, whey protein is 150 times, 300 times of copper, Alternatively, even when it is 1000 times, it is possible to prepare a copper-bound whey protein having a copper binding rate of 80% or more.

[Test Example 4]
In the production method of the present invention, this test was conducted when the copper-bound whey protein was used as the copper source, and when copper sulfate was used, the peroxide value and the hexanal amount of the prepared milk powder produced under the respective conditions. Went to measure.

(1) Preparation of Sample A sample of this test was prepared by preparing a copper-bound whey protein solution in the same manner as in the step (1) of Example 2, and using this copper-bound whey protein solution, Example 2 Prepared milk powder produced by the same method as in (2) to (4) was used as a test sample.
On the other hand, prepared milk powder produced using copper sulfate instead of the copper-bound whey protein solution was used as a control sample.

The manufacturing method of a control sample is shown. First, 1160 g of skim milk (Morinaga Milk Industry), 500 g of desalted whey powder (made by Domo), 59 g of lactose (made by Mirai), and 52 g of dextrin (made by Toyo Sugar Co.) are dissolved in 2380 g of water and previously dissolved with caustic soda. Then, it was mixed with 143 g of 10% casein solution deodorized. This was further mixed with 240 g of fish oil blended prepared fat (manufactured by NOF. Fish oil containing 1.5 g per 100 g of fat and oil) and 33 g of unsalted butter (manufactured by Morinaga Milk Industry) and homogenized under a pressure condition of 15 MPa, then 125 Sterilized at 2 ° C. for 2 seconds, homogenized under a pressure condition of 15 MPa, and then concentrated to a solid content of 50% to prepare a concentrated solution.
Subsequently, 13 mg of copper sulfate (manufactured by Tomita Pharmaceutical), 307 mg of ferric pyrophosphate (manufactured by Tomita Pharmaceutical), and 104 mg of zinc sulfate (manufactured by Tomita Pharmaceutical) are dissolved in 50 g of water, and this is cooled to 10 ° C. or lower to be mineral. A solution was prepared, this mineral solution was added to the previously prepared concentrated solution, and spray-dried by a conventional method to prepare a control sample.

(2) Test method
a) Sensory evaluation test In the sensory evaluation test, samples were evaluated in the same manner as in Test Example 1.

b) Measurement of peroxide value About 10 g of fats and oils are accurately weighed from the sample used in the sensory evaluation test, placed in a stoppered Erlenmeyer flask, added with 35 ml of chloroform / glacial acetic acid mixture (2: 3), and then dissolved. Add 1 ml of saturated potassium iodide solution while passing the air in the flask through nitrogen gas or carbon dioxide, immediately plug and mix for about 1 minute, then titrate with 0.01 N sodium thiosulfate solution using starch test solution as indicator. did. Separately, a blank test was performed by operating in the same manner.

The peroxide value was determined by the following formula.
Peroxide value (meq / kg) = [(a × F) / S] × 10
Where S: Amount of sample collected (g)
a: Consumption of 0.01N sodium thiosulfate solution (ml)
F: Potency of 0.01N sodium thiosulfate solution

c) Measurement of the amount of hexanal The amount of hexanal in the sample was measured using a solid-phase microextraction gas chromatograph mass spectrometer (GC / MS: manufactured by Agilent) for the sample used in the sensory evaluation test.

(3) Test results The results of this test are as shown in Table 4. Table 4 shows prepared milk powder produced using a copper-bound whey protein solution prepared at a final whey protein concentration of 4% by mass, and prepared milk powder produced using a copper sulfate solution instead of the copper-bound whey protein solution. It is a table | surface which shows the peroxide value of and the amount of hexanal.
As a result, the prepared milk powder (test sample) produced using a copper-bound whey protein solution prepared to a final whey protein concentration of 4% by mass as the copper supply source had a peroxide value of 0.78 meq / kg. Yes, the amount of hexanal was 0.54 ppm. That is, it was found that the formula milk produced by the method of the present invention was effectively suppressed even after 2 months and the amount of hexanal was low, so that the sensory evaluation was given the “best” overall evaluation.
On the other hand, in formula milk powder (control sample) whose copper source is copper sulfate, the oxidation progresses after 2 months and the amount of hexanal is about 3 times that of the test sample. It was found that a comprehensive evaluation of “bad” can be obtained.

[Test Example 5]
In the production method of the present invention, this test is a sensory evaluation of the preservability of the prepared milk powder produced under the respective conditions when copper-bound whey protein is used as the copper source and when copper sulfate is used. This was done to evaluate based on the test.

(1) Preparation of sample The concentration of whey protein used for addition was changed from 4.3% by mass to 4.8% by mass, whereby the final whey protein concentration of the mixture of copper solution and whey protein solution was changed. A copper-bound whey protein solution was prepared in the same manner as in step (1) of Example 2 except that the amount was 4.5% by mass, and the preparation produced using this copper-bound whey protein solution Powdered milk was used as a test sample.
In addition, a control sample was prepared by the same method as the control sample manufacturing method of Test Example 4.

(2) Test method The sensory evaluation test of each sample was conducted in the same manner as in Test Example 1 except that the storage period of b) Sensory evaluation test was changed to 1 month, 2 months and 3 months, respectively. It was.

(3) Test results The results of this test are as shown in Table 5. Table 5 shows the preparation of milk powder prepared using a copper-bound whey protein solution prepared to a final whey protein concentration of 4.5% by mass, and a copper sulfate solution instead of the copper-bound whey protein solution. It is a table | surface which shows the relationship between a preservation | save period and sensory evaluation in formula milk powder.
As a result, the prepared milk powder produced by the method of the present invention (the final whey protein concentration of the copper-bound whey protein solution is 4.5% by mass) has a sensory evaluation of “best” even if stored for 2 months. It was found that even after 3 months, the sensory evaluation gave a “good” overall evaluation.
On the other hand, in the formula powdered milk (control sample) whose copper source is copper sulfate, the sensory evaluation was “good” after 1 month, but the sensory evaluation was already after 2 months. The overall evaluation was “bad”, and the flavor and appearance were not preferable due to the progress of oxidation.

[Test Example 6]
This test uses copper-bound whey protein, copper-bound lactoferrin, or copper sulfate as the copper source (copper raw material). When each copper raw material is added to an emulsion containing fats and oils, The effect on the oxidation of the products was evaluated based on the amount of hexanal generated from the emulsion.

(1) Preparation of sample Preparation of emulsion Liquid casein was dissolved in an aqueous solution of caustic soda and further deodorized to prepare a 10% casein solution. 2 L of this casein solution and 0.4 L of fish oil were mixed. After heating this liquid mixture to 60 degreeC, it homogenized at the pressure of 15 Mpa, and prepared the emulsion.

(2) Sample preparation [Example 1] The copper-bound whey protein obtained by the method of (1) was used as a copper-bound whey protein.
Separately, 1 L of a solution containing 1M sodium bicarbonate (A solution), 0.2 L of a solution containing 100 mM copper sulfate (B1 solution), and 0.8 L of a solution containing 1 mM lactoferrin (B2 solution) were prepared. First, the B solution obtained by mixing the B1 solution and the B2 solution was added to the A solution and stirred to prepare a solution containing lactoferrin to which copper sulfate was bound. Then, 300 mL of this solution was dialyzed against ultrapure water with a dialysis membrane having a molecular weight of 10,000 cut to remove the unbound copper and completely desalted, and then freeze-dried to prepare copper-bound lactoferrin. .
In addition, the method of the test example 1 of patent document 2 was referred for the manufacturing method of copper bond lactoferrin. Moreover, the copper bond lactoferrin used what was made into the aqueous solution as a copper raw material.
A copper sulfate solution was used as another copper raw material.

(3) Test method Each copper raw material was added to 100 ml of the emulsion. The emulsion (copper-containing emulsion) to which each copper raw material was added was prepared to have a copper concentration of 80 μM and sealed in a plastic tube. These samples were stored at 45 ° C. for 4 days in the dark.
About each sample after storage period (4 days) progress, the amount of hexanals was measured by the method similar to the measurement of the test method (2) c) hexanal content of Test Example 4.

(4) Test results As a result, when copper sulfate was used as the copper raw material, the amount of hexanal generated as compared with the case where the copper-bound whey protein used in the present invention was added to the emulsion as the copper raw material. Increased by 50%, and it became clear that the progress of oxidation of the emulsion was promoted.
Furthermore, even when copper-bound lactoferrin is used as the copper raw material, the amount of hexanal generated is about 56% higher than that when copper-bound whey protein is used as the copper raw material. Was. This shows the progress of oxidation of the emulsion similar to the case of using copper sulfate, and it is difficult to obtain an effect sufficient to suppress oxidation by copper with a protein of lactoferrin alone. Was shown.
That is, as is clear from this test, the effect of promoting the oxidation of lipid by copper is that the progress of oxidation is suppressed when copper is combined with whey proteins such as WPC used in the present invention. It was revealed that the purified lactoferrin single protein cannot be expected to have the effect of the present invention.
Whey protein contains a small amount of lactoferrin in its constituents [Milk General Encyclopedia, Asakura Shoten, 1998, 3rd edition, page 70. That is, 0.01 (upper limit of lactoferrin content in milk: wt%) / 0.6 (whey protein content in milk: wt%) × 100 = 1.7%]. However, it is clear from the above test results that a stronger oxidation-inhibiting effect is obtained when whey proteins (WPC, etc.) bind to copper than when lactoferrin binds to copper alone. became. From this fact, components other than lactoferrin in whey protein (for example, whey protein containing about 1.7% or less of lactoferrin) are involved in the formation of copper-bound whey protein, so that It was suggested that it works as a factor that functions to inhibit lipid oxidation.
If WPC used in the examples of the present invention is used as whey protein, lactoferrin in WPC is 1.3% or less [0.8 (milk in WPC when WPC is 1). (Mass ratio of purified protein) × 0.01 (upper limit of lactoferrin content in milk: wt%) / 0.6 (whey protein content in milk: wt%) × 100 = 1.3%] It was also suggested that lipid oxidation by copper can be effectively suppressed when lactoferrin is used at about 1.3% or less of WPC.

  The manufacturing method of the formula milk (prepared milk powder and liquid formula milk) of this invention can be widely utilized as a manufacturing method of formula milk containing a metal and an unsaturated fatty acid. In particular, it contains milk proteins such as whey protein, and can be suitably applied to methods for producing foods, beverages, pharmaceuticals, and feeds that are produced by mixing fats and oils and metal components in the liquid, for the purpose of inhibiting oxidation. It can be applied as a simple method that does not require any new raw materials.

Claims (9)

An aqueous solution of copper, with a solution of whey protein concentration to be 0.7 to 8.0 mass% in terms of a final concentration after mixing with an aqueous solution of copper, were mixed, copper-binding of 80% or more Preparing a copper-bound whey protein solution of
And copper-binding whey protein solution prepared, proteins, fats and oils containing unsaturated fatty acids, sugars, and modified milk raw material containing minerals (except, prepared milk materials are treated previously homogenized) and in a liquid Mixing in step to prepare liquid formula
A step of heat sterilizing the prepared liquid formula,
A process of producing liquid milk powder by drying the heat-sterilized liquid formula;
The manufacturing method of formula milk powder containing this. The step of preparing a copper-bound whey protein solution comprises:
The method according to claim 1 , wherein the whey protein is mixed with copper and whey protein at a ratio of 60 parts by mass or more with respect to 1 part by mass of copper. The step of preparing liquid formula is
The method of Claim 1 or 2 performed by mixing the prepared copper bond whey protein solution and the solution of a raw material for prepared milk. The method according to any one of claims 1 to 3, wherein the produced milk powder has a peroxide value of 0.8 meq / kg or less when stored for 2 months at room temperature. The method according to any one of claims 1 to 4, wherein the amount of hexanal contained in the prepared formula when the prepared formula is stored at room temperature for 2 months is 0.6 ppm or less. The method according to any one of claims 1 to 5, wherein in the step of preparing the liquid formula milk, a formula milk raw material sterilized by heating in advance is used as the formula milk raw material. The step of heat sterilizing the prepared liquid formula and the step of drying the heat sterilized liquid formula and producing the prepared powdered milk,
Heating the prepared liquid formula and drying it to produce formula milk;
The method according to any one of claims 1 to 6 , wherein the method is performed by: An aqueous solution of copper, with a solution of whey protein concentration to be 0.7 to 8.0 mass% in terms of a final concentration after mixing with an aqueous solution of copper, were mixed, copper-binding of 80% or more Preparing a copper-bound whey protein solution of
And copper-binding whey protein solution prepared, proteins, fats and oils containing unsaturated fatty acids, sugars, and modified milk raw material containing minerals (except, prepared milk materials are treated previously homogenized) and in a liquid Mixing in step to prepare liquid formula
A step of heat sterilizing the prepared liquid formula,
A method for producing liquid formula, comprising: Liquid formula milk manufactured by the method of Claim 8 .